The present invention relates generally to surgical cutting instruments, and more particularly to surgical scalpels having retractable blades.
It is well known that existing surgical cutting implements provide a significant potential for harm to surgeons and support personnel. That is, with attention directed toward the patient, rapid handling of surgical instruments with exposed sharp edges occasionally leads to cuts and puncture wounds, and more often to loss of integrity of surgical gloves. With increasing risk of life-threatening infectious diseases, it is imperative that such risks be minimized.
Utility knives having retractable blades are well known. For example, U.S. Pat. No. 4,805,304 for "Utility Knife Having A Sliding Blade Holder," which issued to Heinz-Pete Knoop on Feb. 21, 1989, describes a knife with a substantially hollow handle having a knife blade guided longitudinally in a knife blade guide track and at least one slider member coupled with the handle side of the longitudinally movable knife blade. The slider member penetrates a wall of the handle in a slider member longitudinal slot in the handle broad side. The slot opens at both broad sides. The slider member has on each of the handle broad sides an operating piece engageable by a thumb. Both of the operating pieces receive between themselves and the knife blade at least one guide strip extending parallel to the handle longitudinal axis. The slider member is spring loaded for retraction and requires continuous thumb operation unless a locking device is employed. Thus, if the thumb is removed and a locking device is not employed, the knife blade is automatically pulled back into the knife handle.
Similarly, surgical knives have been described wherein various types of blade protection is available. U.S. Pat. No. 3,905,101 for "Disposable Surgical Scalpel," issued to John W. Shepherd on Sept. 16, 1975. Therein is described a single, monassembly, disposable surgical scalpel which includes a handle, a cutting blade attached to the handle, a sheath movably attached to the handle, means for releasably locking the sheath whereby the blade is sheathed, and means for releasably locking the sheath in a position which exposes the blade. Although the sheathable instrument taught by Shepherd would achieve the desired increase in safety for operating room personnel, two hands are required to operate the locking mechanism, thereby rendering the instrument considerably more cumbersome to use than conventional scalpels.
Similarly, for U.S. Pat. No. 2,735,176 for "Veterinary Surgical Knife," which issued to William J. Costin on May 22, 1953. Therein is described a surgical knife which includes a hollow ground blade of surgical steel and a hollow handle into which the blade can be fully retracted for protection while the blade is not in use and from which the edged portion of the blade can be projected for use with the blade disposed substantially in longitudinal alignment with the handle. The locking mechanism taught includes a threaded pin attached to the blade which extends through a slot in the handle, and a knob which is threaded onto the pin for locking the blade in either an extended or withdrawn position. Two hands are required for successful operation of the Costin invention.
Accordingly, it is an object of the present invention to provide surgical scalpels having retractable blades which may be locked in either a deployed or a retracted position.
Another object of our invention is to provide surgical scalpels having retractable blades which may be locked in either a deployed or a retracted position and which may be operated using one digit of one hand.
Yet another object of the invention is to provide surgical scalpels having retractable blades which may be locked in either a deployed or retracted position, but which cannot accidentally be deployed.
Still another object of our invention is to provide surgical scalpels having retractable blades for which blades may be changed during a surgical procedure.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.